There is known a technology of enabling movement in a virtual reality space (hereinafter also simply referred to as “virtual space”). For example, in Japanese Patent No. 5838278 (Patent Document 1), there is disclosed a technology for “providing a simulation game with a higher game quality”. In Japanese Patent Application Laid-open No. 2001-338311 (Patent Document 2), there is disclosed a “virtual reality space movement control device configured to enable a user to easily grasp where the user is located in a virtual space and easily move to a location or scene of interest for the user without an unnecessary and complicated space movement operation”. This virtual reality space movement control device is used to “move freely in the virtual space to view the virtual space by operating an input device, for example, a mouse”. Further, the virtual reality space movement control device “includes a sub-screen for assisting in movement in a virtual world independently of a main screen for displaying the virtual world, displays a plan view of the entire virtual space being explored by the user on a sub-screen frame, displays a camera mark indicating a current camera position and an eye-gaze direction on the plan view, and includes virtual space exploration guidance means for receiving an instruction to move in the virtual space to assist the user in exploring the space, to thereby solve the above-mentioned problem” (refer to “Abstract”).